diff --git a/scripts/completion/ccs.bash b/scripts/completion/ccs.bash
index 815f27a1..b9eb965e 100644
--- a/scripts/completion/ccs.bash
+++ b/scripts/completion/ccs.bash
@@ -156,7 +156,7 @@ _ccs_completion() {
     case "${prev}" in
       env)
         # Complete with profile names and flags (inline profiles since $cliproxy_profiles is out of scope)
-        local env_opts="--format --shell --help -h gemini codex agy qwen"
+        local env_opts="--format --shell --help -h gemini codex agy qwen iflow kiro ghcp claude"
         if [[ -f ~/.ccs/config.json ]]; then
           env_opts="$env_opts $(jq -r '.profiles | keys[]' ~/.ccs/config.json 2>/dev/null || true)"
         fi
diff --git a/src/commands/env-command.ts b/src/commands/env-command.ts
index 843b8c01..e461c32e 100644
--- a/src/commands/env-command.ts
+++ b/src/commands/env-command.ts
@@ -197,6 +197,11 @@ export async function handleEnvCommand(args: string[]): Promise<void> {
   const format = formatStr as OutputFormat;
 
   const shellStr = parseFlag(args, 'shell') || 'auto';
+  const validShellInputs = ['auto', 'bash', 'zsh', 'fish', 'powershell'];
+  if (!validShellInputs.includes(shellStr)) {
+    console.error(fail(`Invalid shell: ${shellStr}. Use: ${validShellInputs.join(', ')}`));
+    process.exit(1);
+  }
   // zsh uses the same syntax as bash
   const shell = detectShell(shellStr === 'zsh' ? 'bash' : shellStr);
 
diff --git a/tests/unit/commands/env-command.test.ts b/tests/unit/commands/env-command.test.ts
index d70a140c..b6da6236 100644
--- a/tests/unit/commands/env-command.test.ts
+++ b/tests/unit/commands/env-command.test.ts
@@ -103,6 +103,12 @@ describe('env-command', () => {
       );
     });
 
+    it('prevents backtick injection in values', () => {
+      expect(formatExportLine('bash', 'TOKEN', 'safe`whoami`')).toBe(
+        "export TOKEN='safe`whoami`'"
+      );
+    });
+
     it('escapes single quotes in fish values', () => {
       expect(formatExportLine('fish', 'VAL', "it's here")).toBe("set -gx VAL 'it'\\''s here'");
     });